1. Field of the Invention
This invention generally relates to the field of digital communications, and more particularly relates to a system and method for providing a soft-decision trellis-coded, differential frequency-hopped spread spectrum waveform and decoder.
2. Description of Related Art
Spread spectrum communication techniques such as frequency hopping (FH) and direct sequence spread spectrum (DSSS) provide processing gain for users, thereby providing a reliable communications method for users. However, in the presence of many users, co-channel interference degrades the performance of the existing spread spectrum techniques. In addition, in some applications, it is desirable that the waveforms have a low probability of detection (LPD) by unintended receivers and the waveform is resilient in the presence of jamming signals (i.e. is anti-jam (AJ)). None of the existing spread-spectrum waveforms provide a signal that is simultaneously LPD, AJ, allows multiple simultaneous asynchronous users occupying the same time and frequency bands (conferencing), and is easily implemented.
Therefore a need exists to overcome the problems with the prior art as discussed above, and particularly for a system and method for providing a soft-decision trellis-coded, differential frequency-hopped spread spectrum waveform and decoder that produces improved AJ and LPD performance.